Left knee brushing top tube on new bike

daniel_b

Afternoon all,

a bit of a ponder.

I thought my knees tracked pretty straight, on my CR1 and turbo bikes, I have never noticed an issue with the closeness of either to the top tube, in fact if anything I thought it was my right knee that canted in at the top of the peal stroke slighly.

I currently use the same shoes and cleats to ride both the CR1 and my new foil, which has a much chunkier top tube.

But when riding the foil, not all the times, but occasionally my left knee makes light contact with the top tube.
So I am wondering if I need to try and tweak the cleat position marginally (Seems the easiest DIY approach) and if so whether I try and keep the same cleat orientation, but slide it left or right if that makes sense, and or whether I try and rotate the cleat slightly, to put my heel more in or out.
I did used to have my cleats set with more heel in than I do now, so my heels used to just clear the rear stays, but I seemed to have straightened out over the years.

I've set the saddles at the same height so as to give the same bend in the knee, though I appreciate this is a bit of an approximation using a goniometer thingy.
I can't swear to it, but I think I measured BB to top of saddle on CR1 and replicated this onto the Foil - although the CR1 as 175 cranks, and the Foil has 172.5, so the saddle on the Foil should\could be 2.5mm higher, and I wonder if I might have gone lower by accident, which would still only be 5mm of difference, but that could potentially make a difference?

EDIT: And just to add, it's a proprietary non round seatpost, so the saddle has no choice but to be aligned perfectly!

photonic69

Try footbeds with better arch support in your shoes, I had a very similar problem and these solved it:

https://www.specializedconceptstore.co. ... -footbeds/

zefs

I have the same issue on my longer leg, but from my experience lowering the saddle make things better rather than having it higher, because it "fixes" the asymmetry. So it can come from anywhere, like longer femur or leg bow, the pelvis/spine etc.

It could also be coming from the saddle and not sitting completely square on it (most people don't, it's just how the body works). Does the Foil have narrower q-factor by any chance? (different cranks).

daniel_b

Thanks gents, I do have some Diadora oven footbeds I could give a go, bought a while ago but never got around to trying them.

I don't know off the top of my head re the Q factor, chainsets are same make, just Ultegra versus Dura ace.

Both bikes have Vector two pedals fitted, on the foil I had to fit just one of the 1 or 2mm spacers so the chain didn't rip the sensor off the back of the pedal - don't think I read anything that said you had to match this on the other side though, but I guess that would make it not quite central.

chris_bass

have you ridden the old bike again since noticing? do you get the same thing on that bike now too or just on the new one?

daniel_b

Chris Bass wrote:

have you ridden the old bike again since noticing? do you get the same thing on that bike now too or just on the new one?

Yes I have, and no only on the new bike.

Shoes and pedals are identical, save for the one spacer on the drive side of new bike.
Main visual difference is width of top tube on new bike.

Though have not looked down and noted how close knees get on the CR1, will probably do that next actually, good call.

Ben6899

It sounds like your fit is different between the old bikes and the new one.

Have you compared setups/measurements?

Matthewfalle

how about just riding with your left leg out a tad?

#rubbing

daniel_b

Ben6899 wrote:

It sounds like your fit is different between the old bikes and the new one.

Have you compared setups/measurements?

I have matched up most measurements - although the one difference is that the reach to the hoods is approx 10mm more on this bike - unavoidable due to the integrated bar and stem.
However I have been elongating myself over the last 10 months on the turbo bike, and continue to do so.
My CR1 did have a 90mm stem, but a few weeks ago I went up to a 100mm, and have adapted to that pretty quickly, including prolonged time in the drops, so probably late June will swap it out to the 110mm I have sat in the wings ready to go.

I have not compared them down to the level of frame geometry - position of knee over the pedal etc etc.

The foil has an effective 110mm stem, and both are 54's.

Can't recall if drop on the foil is a bit more than the CR1, entirely possible, but it's ridiculously comfy in the drops, way more than I imagined.

I noticed the top tube on the CR1 is actually fatter than I thought - not had time to measure it yet, but not as far removed from the foil I don't think.
The turbo bike on the other hand is old school ali and from 2005, so nice and thin tubing.
I had a session this morning, and my left knee is a tad closer than the right.

Not much in it though, so will try the insoles I have sat in stock first anyway.

I do have a retul bike fit voucher (gifted to me at Christmas) to use, but plan to have that done on the CR1 (Once I am up to the 110mm stem), rather than the foil, as it will be ridden more and for longer distances, but then I can hopefully translate the output from that across to the foil IF required.
I have been gradually tinkering with my position for some 12 odd years now, so will be interested to see what the bike fit reveals, though I am mostly hoping it says all is pretty much where it needs to be.
My comfort on the bike has increased hugely, especially in the last two years.

@MF - yes I could do I suppose, mind over matter!